Fixes #32 (#49)

Default-construct `xwhat` and filter out empty ones in order to allow more Valgrind output.

src/valgrind/mod.rs

@@ -76,8 +76,23 @@ where
         listener
             .read_to_end(&mut output)
             .map_err(|_| Error::SocketConnection)?;
-        let xml: xml::Output =
-            serde_xml_rs::from_reader(&*output).map_err(|e| Error::MalformedOutput(e, output))?;
+        let xml: xml::Output = serde_xml_rs::from_reader(&*output)
+            .map(|output_: xml::Output| {
+                let mut output = output_;
+                if let Some(err) = output.errors {
+                    let new_err: Vec<xml::Error> = err
+                        .into_iter()
+                        .filter(|e| e.resources.bytes > 0 || e.resources.blocks > 0)
+                        .collect();
+                    if new_err.len() > 0 {
+                        output.errors = Some(new_err)
+                    } else {
+                        output.errors = None
+                    }
+                }
+                output
+            })
+            .map_err(|e| Error::MalformedOutput(e, output))?;
         Ok(xml)
     });
 

src/valgrind/xml/mod.rs

@@ -55,6 +55,7 @@ pub struct Error {
     #[serde(deserialize_with = "deserialize_hex")]
     unique: u64,
     pub kind: Kind,
+    #[serde(default)]
     #[serde(rename = "xwhat")]
     pub resources: Resources,
     #[serde(rename = "stack")]
@@ -152,6 +153,15 @@ fn deserialize_hex<'de, D: Deserializer<'de>>(deserializer: D) -> Result<u64, D:
     deserializer.deserialize_str(HexVisitor)
 }
 
+impl Default for Resources {
+    fn default() -> Self {
+        Resources {
+            bytes: 0,
+            blocks: 0,
+        }
+    }
+}
+
 /// A visitor for parsing a `u64` in the format `0xDEADBEEF`.
 struct HexVisitor;
 impl<'de> Visitor<'de> for HexVisitor {